Passenger airbag with secondary chamber

ABSTRACT

A vehicle airbag comprises a primary chamber and a secondary chamber affixed to the primary chamber by a seam. A passage is defined between the primary chamber and the secondary chamber. The seam defines a closed shape, and an inner side of the seam is located between sides of the primary chamber, and is between sides of the secondary chamber.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of, and as such claimspriority to, U.S. patent application Ser. No. 14/209,752, filed Mar. 13,2014, entitled “PASSENGER AIRBAG WITH SECONDARY CHAMBER,” whichapplication is hereby incorporated herein by reference in its entirety.

BACKGROUND

A potential cause of head injuries in vehicle collisions, particularlywhen a collision includes an oblique impact, is a rotation of a vehicleoccupant's head. For example, vehicles traveling in opposite directionsmay collide at an angle, striking each other on a driver's side of atarget vehicle. In this scenario, an occupant in a passenger-side seatof the target vehicle may experience head rotation, that consequentlymay induce head injury, as the occupant's head strikes a passengerairbag and rolls toward the driver's side of the vehicle. Presentpassenger airbags may not be problematic with head rotation in a directhead-on collision. However, present passenger airbags have deficiencieswith respect to their ability to minimize head rotation and head injuryin oblique collisions.

DRAWINGS

FIG. 1 is a block diagram of first and second vehicles on an obliqueimpact collision course.

FIG. 2 is a perspective view of a vehicle portion including a passengerairbag having a primary chamber and a secondary chamber.

FIG. 3 is a top cross-sectional view of a vehicle portion including apassenger airbag having a primary chamber and a secondary chamber.

FIG. 4 is a further top cross-sectional view of a vehicle portion 4including a passenger airbag having a primary chamber and a secondarychamber, showing a human head striking the airbag upon an obliqueimpact.

FIG. 5 is a perspective view of a vehicle portion including a passengerairbag having a primary chamber and a secondary chamber.

FIGS. 6A-6E provide respective perspective views of exemplary secondarychambers attached to a primary chamber.

FIGS. 7A and 7B are perspective views of respective exemplary airbags10, illustrating exemplary mechanisms for affixing the secondary chamber12 to the primary chamber 11.

FIG. 8 provides a graph showing respective Brain Injury Criterion (BrIC)scores for airbags with and without a secondary chamber.

FIG. 9 includes two series of block diagrams representing times-seriessimulations of a human head striking an airbag.

FIG. 10 is a perspective view of a vehicle portion including a furtherexample of a passenger airbag having a primary chamber and a partiallyattached secondary chamber.

FIG. 11 is a top cross-sectional view of a vehicle portion including theexemplary passenger airbag of FIG. 10, having a primary chamber and apartially attached secondary chamber.

FIGS. 12A-12C provide respective perspective views of the exemplaryairbag of FIG. 10, including exemplary secondary chambers partiallyattached to a primary chamber.

FIG. 13 includes three series of block diagrams representingtimes-series simulations of a human head striking an airbag.

FIG. 14 provides a graph showing respective Brain Injury Criterion(BrIC) scores for airbags without a secondary chamber, with a secondarychamber that is fully attached, and with a secondary chamber that ispartially attached.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of first and second vehicles 1, 2 on anoblique impact collision course. As illustrated in FIG. 1, the vehicles1, 2 will strike each other at an angle 3, defined by longitudinal axesA, B of the vehicles 1, 2, respectively. In the example of FIG. 1, theangle 3 is 15 degrees, which is an angle used in an oblique impact testmode of the National Highway Transportation and Safety Administration(NHTSA). Accordingly, when the vehicle 2 strikes the vehicle 1, apassenger seated in the vehicle 2 will be moved in a direction at anangle to the axis B of the vehicle 2. For example, the passenger couldmove in a general direction of the arrow C; the direction of thepassenger's movement being determined by a variety of known factors,such as speed, angle of impact, center of gravity of the vehicles 1, 2,etc. In this scenario, a passenger seated in the vehicle 2 mayexperience head rotation, and more severe head injury that would havebeen experienced in a head-on collision, e.g., measured by a BrainInjury Criterion (BrIC) score, such as is known.

FIG. 2 is a top perspective view of a vehicle portion 4. The vehicleportion 4 includes a passenger airbag 10 having a primary chamber 11 anda secondary chamber 12, the airbag 10 being shown in an inflated stateafter having been deployed from a vehicle dash panel 14. The airbag 10is generally constructed from conventional materials, and may bedeployed in a conventional manner, including as described below.

As can be seen in FIG. 2, and as is further illustrated below, thesecondary chamber 12 is positioned to mitigate a tendency of a vehicleoccupant's head to roll or rotate upon an oblique impact. That is,although the airbag 10 is shown on a passenger's side of a vehicle(assuming a left-hand drive), and the secondary chamber 12 is thuslocated to the left of the primary chamber 11, to thereby mitigate headrotation in a direction toward the secondary chamber 12. Alternativelyor additionally, the secondary chamber 12 could be located to the rightof the primary chamber 11. For example, to protect the front passengerif the passenger side is the struck side such as vehicle 1 in FIG. 1, orin countries where a passenger's side of a vehicle is on the left ratherthan the right, it could be desirable to place the secondary chamber 12to the right of the primary chamber 11. Further, it is possible toinclude two or more secondary chambers 12 affixed to the primary chamber11, e.g., one to the left as shown in FIG. 2, and another to the right.

As best seen in FIG. 5, and also illustrated in FIG. 2, the primarychamber 11 contacts first and second reaction surface when the airbag 10is inflated. That is, the primary chamber 11 contacts the dash orinstrument panel 14, as well as a vehicle windshield 29, when the airbag10 is inflated. The secondary chamber 12, in contrast, contacts only onereaction surface when the airbag 10 is inflated, e.g., the instrumentpanel 14.

FIG. 3 is a top cross-sectional view of a vehicle portion 4 including apassenger airbag 10 in an inflated state. The airbag 10 includes aprimary chamber 11 and a secondary chamber 12. The vehicle dash 14 hasdisposed therein an inflator 18, such as is known. As is further known,inflator 18, upon a triggering event, e.g., a collision, being detectedby an airbag controller (not shown), may inflate the airbag 10 via aninflator valve 20.

FIG. 3 further illustrates passage 16 between the primary chamber 11 andthe secondary chamber 12. For example, the secondary chamber 12 may beaffixed to the primary chamber 11 using conventional mechanisms, e.g.,sewn, glued, bonded, etc., wherein a wall 15 may be defined between theprimary chamber 11 and the secondary chamber 12, and further wherein anopening may be left in a seam connecting the primary and secondarychambers 11, 12 to create the passage 16. Alternatively or additionally,the passage 16 may include an opening having disposed therein a one-wayvalve 17 or the like to allow gases to travel from the primary chamber11 to the secondary chamber 12 upon an event such as a collisiontriggering inflation of the airbag 10. Although the passage 16 is shownas rectangular in FIG. 3, often it is circular, and/or the valve 17 maybe omitted, as seen in FIGS. 7A and 7B.

FIG. 7A is a perspective view of an exemplary airbag 10, illustrating anexemplary mechanism for affixing the secondary chamber 12 to the primarychamber 11. Specifically, in the example of FIG. 7A, the secondarychamber 12 is affixed to a wall 23 of the primary chamber 11 withstitching along a set of seams 19 defined by a perimeter of thesecondary chamber 12 affixed to the wall 23.

FIG. 7B is a perspective view of an exemplary airbag 10, illustrating anexemplary mechanism for affixing the secondary chamber 12 to the primarychamber 11. Specifically, in the example of FIG. 7B, similar to theexample of FIG. 7A, the secondary chamber 12 is affixed to a wall 23 ofthe primary chamber 11 with stitching along a set of seams 19. However,because in the exemplary airbag 10 of FIG. 7B (as in the exemplaryairbag 10 including a secondary chamber 12 e, discussed below withrespect to FIG. 6E), the secondary chamber 12 extends to a great heightthan does the primary chamber 11, the set of seams 19 do not extend allthe way around a perimeter of a side of the secondary chamber 12.Instead, some of the seams 19 define a portion of the perimeter of aside of the secondary chamber 12 attached to the wall 23. A remainingsubset of one or more of the seams 19 generally coincide with a top edge24 of the wall 23, the edge 24 being where the secondary chamber 12 isjoined to the wall 23 of the primary chamber 11.

The size of an opening in the passage 16, and/or a rate at which thepassage 16, including possibly the one-way valve 17 therein, isconfigured to allow gases to move from the primary chamber 11 to thesecondary chamber 12, may depend on a variety of factors. For example,the airbag 10 may vary in size and configuration depending on a typeand/or size of vehicle in which it is installed. Further, an airbagcontroller could be configured to control a valve in the passage 16depending on various conditions. For example, the valve 17 could beopened if an oblique impact was detected, but left closed, i.e., suchthat the secondary chamber would not inflate, if a direct frontal orhead-on collision was detected. Likewise, control of a valve 17 coulddepend on other crash modes, e.g., the valve 17 could be configured toopen in an offset deformable barrier (ODB) crash mode used in crashtesting.

Yet further, a degree to which a valve 17 is open could depend on adetected or predicted angle of the oblique impact. For example, where anangle of impact is greater, e.g., greater than 15 degrees, greater than30 degrees, etc., it may be desirable to open the valve 17 all the way,or to a greater degree, because in this scenario it would be desirablefor the secondary chamber 12 to be relatively stiff or firm compared tothe primary chamber 11. That is, a stiffness or firmness of thesecondary chamber 12 may be configured to accommodate a predicted angleof impact and consequently likely head rotation of a vehicle passenger.In general, so that a configuration of the passage 16 may controlinflation, stiffness, firmness, etc. of the secondary chamber 12, thesecondary chamber 12 is not vented or provided with openings orpassageways other than the passage 16. The primary chamber 11, on theother hand, may be vented in a conventional manner.

FIG. 4 is a further top cross-sectional view of a vehicle portion 4including a passenger airbag 10 having a primary chamber 11 and a secondchamber 12, showing a human head 22 striking the airbag 10 upon anoblique impact. As shown by the arrow around the circle representing thehead 22, upon an oblique impact, i.e., at an angle to a vehicle axis B,the head 22 is likely to rotate in a clockwise direction as a passengeris moved at an angle to the axis B. To mitigate such rotation, thesecondary chamber 12 is provided. Further, the secondary chamber 12 maybe deployed with a greater firmness than the primary chamber 11 tofurther minimize rotation of the passenger head 22.

FIG. 5 is a side perspective view of a vehicle portion 4 including apassenger airbag 10 having a primary chamber 11 and a secondary chamber12. As with FIG. 4, an arrow is provided to show a direction of rotationof the head 22 of a vehicle passenger upon an oblique impact to thevehicle. As can again be seen, the secondary chamber 12 of the airbag 10provides a barrier to reduce rotation of the passenger head 22, suchbarrier not being provided by the airbag 10 with the primary chamber 11alone.

FIGS. 10-12C illustrate a further possible arrangement of the chambers11, 12 to form the airbag 10, in which the secondary chamber 12 ispartially affixed or attached to the secondary chamber 11 such that agap 30 is provided between respective portions of the primary chamber 11and the secondary chamber 12. As mentioned above, the chambers 11, 12may be joined at a seam by being glued, bonded, sewn, etc.; in thisexample, the seam 19 extends partially, but not completely, around aperimeter of the secondary chamber 12; also, the seam 19 may or may notalso extend partially, but does not extend completely, around aperimeter of the primary chamber 11. In any case, the seam 19 mayinclude an inner side 33 that also borders the gap 30, whereby a side oredge of the gap 30 is defined by the side 33 of the seam 19. As shouldbe clear from the foregoing, the seam 19 generally defines a closedshape, i.e., the seam 19 is generally a contiguous perimeter of someshape, e.g., a square, rectangle, trapezoid, oval, etc., or someapproximation of the following, or of an irregular shape. Further,although the seam 19 is shown in FIGS. 12A-12C as larger than, andsurrounding, the opening 16, in the implementation of an airbag 10 witha partially attached secondary chamber 12 now being described, it is tobe noted that the opening 16 and the seam 19 could be partly or entirelyco-extensive, that is, the seam 19 could define some or all or theboundaries of the opening 19.

As can be seen in FIGS. 12A-12C, the seam 19 in this example generallysurrounds the passage 16, and defines sides or boundaries of the commonwall 15 between the chambers 11, 12. Accordingly, note that the term“gap” as used herein refers simply to facing portions of the chambers11, 12 that do not share the common wall 15. That is, the gap 30 isshown in FIGS. 10 and 11 as providing a space between the chambers 11and 12 for ease of illustration. However, in practice, walls of thechambers 11, 12 on either side of the gap 30 may touch each other, e.g.,as shown in FIGS. 12A-12C. As further seen in FIGS. 12A-12C, an area 35where the gap 30 may be located, with respect to a wall of the primarychamber 11, and with respect to a wall of the secondary chamber 12, isdefined by an area 35 outside a perimeter of the seam 19 where the wall23 of the primary chamber 11 overlaps a wall 32 of the secondary chamber12. For example, the area 35 may be defined by portions of two sides ofthe wall 32 (i.e., by sides of the secondary chamber 12), by the seam 19side 33, and by an edge 37 at which an overlap of the primary chamberwall 23 and the secondary chamber wall 32 terminates.

In other words, for an area bounded by, i.e., having as its perimeter,the seam 19 including the side 33, the wall 23 serves as a common wallbetween the primary chamber 11 and the secondary chamber 12. For thearea 35, however, the wall 23 of the primary chamber 11 is not sharedwith, i.e., is not common to or part of, the secondary chamber 12.Instead, the area 35 is defined on the wall 32 of the secondary chamber,the walls 23 and 32 overlapping at the area 35, and forming the gap 30.Accordingly, the inner side 33 of the seam 19 is located between orinterior to, i.e., not at or near (“near” in this context meaning withintwo centimeters), an edge of either the wall 23 or an edge of the wall32. In general, the inner side 33 is located with respect to whicheverof the walls 23 or 32 has a lesser height (or with respect to either ofthem if the walls 23, 32 have substantially a same height). Further, theinner side 33 may be substantially or roughly parallel to the edge 37,and a location of the inner side 33 may be somewhere between the edge 37and a halfway point of a distance from the edge 37 to an edge, generallyparallel to the edge 37, of one of the walls 23 or 32.

FIGS. 6A-6E respectively provide perspective views of exemplarysecondary chambers 12. Although the secondary chamber 12 has been shownas generally having the shape of a rectangular solid in the precedingillustrations, e.g., in a shape reflected by the secondary chamber 12 ashown in FIG. 6, other shapes may be used depending on various factors,so long as the secondary chamber 12 is configured to contact a singlereaction surface, e.g., the instrument panel 14, when an impact isdetected, whereas the primary chamber 11 is configured to contact atleast two reaction surfaces when an impact is detected, e.g., theinstrument panel 14 and windshield 29. For example, it is generallydesirable to reduce the size and weight of components included in avehicle, including airbags and airbag components. Accordingly, thesecondary chamber 12 may be generally U-shaped, as reflected in theexemplary secondary chamber 12 b, generally trapezoidal or roughlytriangular as reflected in the secondary chamber 12 c, and/or couldinclude an opening as shown with respect to the secondary chamber 12 d.Further, the secondary chamber 12 may be generally rectangular or oblongas illustrated by the secondary chamber 12 e, where the chamber 12 hasat least a length or height greater than a corresponding length orheight of the primary chamber 11, e.g., an end of the chamber 12 extendsbeyond, e.g., is higher than, the primary chamber 11.

FIG. 8 provides a graph showing respective BrIC scores comparison forairbags 10 with and without a secondary chamber 12 according to asimulation. As can be seen, the use of an airbag 10 including a primarychamber 11 and also a secondary chamber 12 results in a roughly 30percent improvement in reduced BrIC score for the vehicle passengercompared to the use of an airbag 10 having a conventional design, i.e.,including a primary chamber 11, but not a secondary chamber 12 asdisclosed herein, in a simulation of an oblique impact in a vehicle.

FIG. 14 provides a graph showing respective BrIC scores for airbags 10without a secondary chamber 12, with a secondary chamber 12 that isfully attached, and with a secondary chamber 12 that is partiallyattached. As can be seen, the use of an airbag 10 including a primarychamber 11 and also a partially attached secondary chamber 12 results ina roughly 37 percent improvement in reduced BrIC score for the vehiclepassenger compared to the use of an airbag 10 having a conventionaldesign, i.e., including a primary chamber 11, but not a partiallyattached secondary chamber 12 as disclosed herein, in a simulation of anoblique impact in a vehicle.

A further illustration of benefits of the presently disclosed airbag 10is provided in FIG. 9, which includes two series of block diagramsrepresenting times-series simulations of a human head 22 striking anairbag 10. A top set of simulations shows a head 22 striking an airbaghaving only a primary chamber 11 at a series of times following animpact, i.e., 52, 60, 66, 70, and 74 milliseconds, respectively. Abottom set of simulations shows a head 22 striking and airbag 10 havinga primary chamber 11 but also a secondary chamber 12 at the same seriesof times following an impact. As can be seen, the airbag 10 includingthe secondary chamber 12 results in less head 22 rotation than theairbag having only a primary chamber 11.

FIG. 13, similar to FIG. 9, includes three series of block diagramsrepresenting times-series simulations of a human head 22 striking anairbag 10 including without a secondary chamber 12 (“BASELINE”), with aprimary chamber 11 and a secondary chamber 12 (“PAB w/SecondaryChamber”), and with a primary chamber 11 and a partially attachedsecondary chamber 12 (“PAB w/Partially Attached Secondary Chamber”). A“BASELINE” set of simulations shows a head 22 striking an airbag havingonly a primary chamber 11 at a series of times following an impact,i.e., 52, 60, 66, 70, and 74 milliseconds, respectively. A “PABw/Secondary Chamber” set of simulations shows a head 22 striking andairbag 10 having a primary chamber 11 but also a secondary chamber 12 atthe same series of times following an impact. As can be seen, the airbag10 including the secondary chamber 12 results in less head 22 rotationthan the airbag having only a primary chamber 11. Further, a “PABw/Partially Attached Secondary Chamber” set of simulations shows a head22 striking and airbag 10 having a primary chamber 11 but also apartially attached secondary chamber 12 at the same series of timesfollowing an impact. As can be seen, the airbag 10 including thesecondary chamber 12 results in less head 22 rotation than the BASELINEseries, and less even than the “PAB w/Secondary Chamber” set ofsimulations.

In the drawings, the same reference numbers indicate the same elements.Further, some or all of these elements could be changed. Accordingly, itis to be understood that the above description is intended to beillustrative and not restrictive. Many embodiments and applicationsother than the examples provided would be apparent to those of skill inthe art upon reading the above description. The scope of the inventionshould be determined, not with reference to the above description, butshould instead be determined with reference to the appended claims,along with the full scope of equivalents to which such claims areentitled. It is anticipated and intended that future developments willoccur in the arts discussed herein, and that the disclosed systems andmethods will be incorporated into such future embodiments. In sum, itshould be understood that the invention is capable of modification andvariation and is limited only by the following claims.

All terms used in the claims are intended to be given their broadestreasonable constructions and their ordinary meanings as understood bythose skilled in the art unless an explicit indication to the contraryin made herein. In particular, use of the singular articles such as “a,”“the,” “said,” etc. should be read to recite one or more of theindicated elements unless a claim recites an explicit limitation to thecontrary.

The invention claimed is:
 1. A vehicle airbag, comprising: a primarychamber; a secondary chamber affixed to the primary chamber by a seam; apassage between the primary chamber and the secondary chamber, whereinthe passage is arranged to provide lateral fluid flow from the primarychamber to the secondary chamber with respect to a longitudinal vehicleaxis; and wherein the seam defines a closed shape, and joins a wall ofthe primary chamber to a wall of the secondary chamber; wherein the seamincludes at least a first side that is not at any edge of the secondarychamber and a second side that is at a first edge of the secondarychamber, whereby the first side of the seam defines an edge of a gapbetween the wall of the secondary chamber and the wall of the primarychamber.
 2. The airbag of claim 1, wherein the seam is at least one ofbonded, glued, and sewn.
 3. The airbag of claim 1, wherein the primarychamber is configured to contact at least two reaction surfaces, and thesecondary chamber is configured to contact one and only one of the atleast two reaction surfaces, when the airbag is inflated upon detectionof an impact.
 4. The airbag of claim 1, further including a one-wayvalve disposed in the passage, the valve being configured to allow gasto flow from the primary chamber to the secondary chamber, wherein anairbag controller is configured to open the valve upon detecting anoblique impact.
 5. The airbag of claim 4, wherein the airbag controlleris configured to open the valve to a degree determined to achieve afirmness of the secondary chamber determined according to a detectedangle of impact.
 6. The airbag of claim 1, wherein a size of the passageis configured to control a firmness of the secondary chamber.
 7. Theairbag of claim 1, further comprising: a second secondary chamberaffixed to the first chamber; and a second passage between the primarychamber and the second secondary chamber, whereby gas provided to thefirst chamber by an inflator mechanism may be provided to the secondsecondary chamber.
 8. The airbag of claim 1, wherein the secondarychamber has one of a length and a height greater than a correspondinglength or height of the primary chamber.
 9. A vehicle airbag,comprising: a primary chamber; a secondary chamber affixed to theprimary chamber by a seam; and a passage between the primary chamber andthe secondary chamber; wherein a first portion of the seam is located ata portion of a perimeter of the secondary chamber and a second portionof the seam has at most a first end and a second end at the perimeter ofthe secondary chamber; wherein the seam includes at least a first sidethat is not at any edge of the secondary chamber and a second side thatis at a first edge of the secondary chamber, whereby the first side ofthe seam defines an edge of a gap between the wall of the secondarychamber and the wall of the primary chamber; and wherein the secondarychamber has one of a length and a height greater than a correspondinglength or height of the primary chamber.
 10. The airbag of claim 9,wherein the seam is at least one of bonded, glued, and sewn.
 11. Theairbag of claim 9, wherein the primary chamber is configured to contactat least two reaction surfaces, and the secondary chamber is configuredto contact one and only one of the at least two reaction surfaces, whenthe airbag is inflated upon detection of an impact.
 12. The airbag ofclaim 9, further including a one-way valve disposed in the passage, thevalve being configured to allow gas to flow from the primary chamber tothe secondary chamber, wherein an airbag controller is configured toopen the valve upon detecting an oblique impact.
 13. The airbag of claim12, wherein the airbag controller is configured to open the valve to adegree determined to achieve a firmness of the secondary chamberdetermined according to a detected angle of impact.
 14. The airbag ofclaim 9, wherein a size of the passage is configured to control afirmness of the secondary chamber.
 15. The airbag of claim 9, furthercomprising: a second secondary chamber affixed to the first chamber; anda second passage between the primary chamber and the second secondarychamber, whereby gas provided to the first chamber by an inflatormechanism may be provided to the second secondary chamber.
 16. Theairbag of claim 9, wherein a location of the second portion of the seamis defined at least in part by one of a point between a top edge of thesecondary chamber and a point halfway between the top edge of thesecondary chamber and a bottom edge of the secondary chamber, and apoint between a top edge of the primary chamber and a point halfwaybetween the top edge of the primary chamber and a bottom edge of theprimary chamber.
 17. A vehicle airbag, comprising: a primary chamber; asecondary chamber affixed to the primary chamber by a seam; a passagebetween the primary chamber and the secondary chamber, wherein thepassage is arranged to provide lateral fluid flow from the primarychamber to the secondary chamber with respect to a longitudinal vehicleaxis; and a one-way valve disposed in the passage, the valve beingconfigured to allow gas to flow from the primary chamber to thesecondary chamber, wherein an airbag controller is configured to openthe valve upon detecting an oblique impact; wherein the seam defines aclosed shape, and joins a wall of the primary chamber to a wall of thesecondary chamber.
 18. The airbag of claim 17, wherein the seam is atleast one of bonded, glued, and sewn.
 19. The airbag of claim 17,wherein the primary chamber is configured to contact at least tworeaction surfaces, and the secondary chamber is configured to contactone and only one of the at least two reaction surfaces, when the airbagis inflated upon detection of an impact.
 20. The airbag of claim 17,wherein the airbag controller is configured to open the valve to adegree determined to achieve a firmness of the secondary chamberdetermined according to a detected angle of impact.